1 /* 2 * Register map access API - SPI support 3 * 4 * Copyright 2011 Wolfson Microelectronics plc 5 * 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/regmap.h> 14 #include <linux/spi/spi.h> 15 #include <linux/init.h> 16 #include <linux/module.h> 17 18 #include "internal.h" 19 20 struct regmap_async_spi { 21 struct regmap_async core; 22 struct spi_message m; 23 struct spi_transfer t[2]; 24 }; 25 26 static void regmap_spi_complete(void *data) 27 { 28 struct regmap_async_spi *async = data; 29 30 regmap_async_complete_cb(&async->core, async->m.status); 31 } 32 33 static int regmap_spi_write(void *context, const void *data, size_t count) 34 { 35 struct device *dev = context; 36 struct spi_device *spi = to_spi_device(dev); 37 38 return spi_write(spi, data, count); 39 } 40 41 static int regmap_spi_gather_write(void *context, 42 const void *reg, size_t reg_len, 43 const void *val, size_t val_len) 44 { 45 struct device *dev = context; 46 struct spi_device *spi = to_spi_device(dev); 47 struct spi_message m; 48 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, }, 49 { .tx_buf = val, .len = val_len, }, }; 50 51 spi_message_init(&m); 52 spi_message_add_tail(&t[0], &m); 53 spi_message_add_tail(&t[1], &m); 54 55 return spi_sync(spi, &m); 56 } 57 58 static int regmap_spi_async_write(void *context, 59 const void *reg, size_t reg_len, 60 const void *val, size_t val_len, 61 struct regmap_async *a) 62 { 63 struct regmap_async_spi *async = container_of(a, 64 struct regmap_async_spi, 65 core); 66 struct device *dev = context; 67 struct spi_device *spi = to_spi_device(dev); 68 69 async->t[0].tx_buf = reg; 70 async->t[0].len = reg_len; 71 async->t[1].tx_buf = val; 72 async->t[1].len = val_len; 73 74 spi_message_init(&async->m); 75 spi_message_add_tail(&async->t[0], &async->m); 76 if (val) 77 spi_message_add_tail(&async->t[1], &async->m); 78 79 async->m.complete = regmap_spi_complete; 80 async->m.context = async; 81 82 return spi_async(spi, &async->m); 83 } 84 85 static struct regmap_async *regmap_spi_async_alloc(void) 86 { 87 struct regmap_async_spi *async_spi; 88 89 async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL); 90 if (!async_spi) 91 return NULL; 92 93 return &async_spi->core; 94 } 95 96 static int regmap_spi_read(void *context, 97 const void *reg, size_t reg_size, 98 void *val, size_t val_size) 99 { 100 struct device *dev = context; 101 struct spi_device *spi = to_spi_device(dev); 102 103 return spi_write_then_read(spi, reg, reg_size, val, val_size); 104 } 105 106 static struct regmap_bus regmap_spi = { 107 .write = regmap_spi_write, 108 .gather_write = regmap_spi_gather_write, 109 .async_write = regmap_spi_async_write, 110 .async_alloc = regmap_spi_async_alloc, 111 .read = regmap_spi_read, 112 .read_flag_mask = 0x80, 113 }; 114 115 /** 116 * regmap_init_spi(): Initialise register map 117 * 118 * @spi: Device that will be interacted with 119 * @config: Configuration for register map 120 * 121 * The return value will be an ERR_PTR() on error or a valid pointer to 122 * a struct regmap. 123 */ 124 struct regmap *regmap_init_spi(struct spi_device *spi, 125 const struct regmap_config *config) 126 { 127 return regmap_init(&spi->dev, ®map_spi, &spi->dev, config); 128 } 129 EXPORT_SYMBOL_GPL(regmap_init_spi); 130 131 /** 132 * devm_regmap_init_spi(): Initialise register map 133 * 134 * @spi: Device that will be interacted with 135 * @config: Configuration for register map 136 * 137 * The return value will be an ERR_PTR() on error or a valid pointer 138 * to a struct regmap. The map will be automatically freed by the 139 * device management code. 140 */ 141 struct regmap *devm_regmap_init_spi(struct spi_device *spi, 142 const struct regmap_config *config) 143 { 144 return devm_regmap_init(&spi->dev, ®map_spi, &spi->dev, config); 145 } 146 EXPORT_SYMBOL_GPL(devm_regmap_init_spi); 147 148 MODULE_LICENSE("GPL"); 149